Process for hydrocracking heavy hydrocarbons

ABSTRACT

A hydrocarbon conversion catalyst consisting essentially of nickel and/or molybdenum and a carrier comprising a crystalline zeolite and a mixture or compound of alumina and magnesia, and the hydrocracking process using this catalyst and heavy hydrocarbon feedstocks in the form of crude oils, shale oils, residual oils and distillates thereof.

0 United States Patent 11 13,617,507

[72] Inventors Willi Oettinger; [50] Field of Search. 208/ l 10 WalterSaum; Roll Seubert, all of Ludwigshafen, Germany Releflillces Cited [21]Appl. No. 798,453 UNITED STATES PATENTS 1 Filed Feb-111969 3.267.0228/1966 Hansford 208/11 1 1 Patented 1971 3.272.734 9/1966 MacLaren 208/110 1 Assign lhdlsche Amlmsodl-Fabflk 3.304.254 2/l967 Eastwood el al208/1 11 Aktienaesellschflfl 3.384.572 5/l968 Myers et al. 208/l 11Ludwisshflem Rhine. Germany 3.450.626 6/!969 Wight et al. 208/1 10 [32]Priorities Feb. 17. 1968 v [33] Germany Primary Lxammer- DelbertE. Gantz[3]] P 16 42 9524); Assistant Exnminer-G. E. SchmItkons Feb- 7 1968.Germany No. P 16 45 7 7 Attorney-Johnston. R001. O'Keeffe. Keil.Thompson 8!.

Shurtleff [54] PROCESS FOR HYDROCRACKING HEAVY g g zfi gfggg g ABSTRACT:A hydrocarbon conversion catalyst consisting essentially of nickeland/or molybdenum and a carrier com- [52] U.S. Cl 208/111, prising acrystalline zeolite and a mixture or compound of alu- 252/455 2 mina andmagnesia. and the hydrocracking process using this [51] Int-Cl Clllg 1catalyst and heavy hydrocarbon feedstocks in the form of COlb 33/28,BOlj ll/54 crude oils. shale oils, residual oils and distillatesthereof.

PROCESS FOR HYDROCRACKING HEAVY HYDROCARBONS it is known that heatresistant compositions containing crystalline zeolites, with or withoutthe addition of catalytically active metals or metal compounds, may beused as catalysts for hydrocarbon conversions such as alkylation,dealkylation of alkylaromatics, isomerizations, hydrofining, catalyticcracking and reforming.

Catalyst compositions and carriers are known for these hydrocarbonconversions which consist exclusively of crystalline zeolites or whichcontain nonzeolitic aluminum silicates or aluminas as well ascrystalline zeolites.

These catalyst compositions and carriers are distinguished by very goodproperties for the said hydrocarbon conversion processes.

it is also known that hydrocracking of high boiling point hydrocarbonscan be carried out in the presence of catalysts which comprise metals ormetal compounds having a catalytic action supported on a crystallinezeolite.

It is further known that hydrocracking may be carried out the presenceof catalysts containing metals or metal compounds whose carrier consistsof a crystalline zeolite which is distributed in an aluminum silicate oralumina which has been prepared from a sol.

These catalysts are distinguished by good cracking activity but in manycases the desired distribution of cracked products is not achieved inthe hydrocracking. Another disadvantage of these catalysts is theirfairly low hydrogenating action.

in processing asphaltic starting material over pure zeolite supportedcatalysts, moreover, the asphalt constituents undergo little or nodegradation in a single passage of the feed. When processing the samefeed over a catalyst which contains (as carrier) not only a crystallinezeolite but also a nonzeolitic aluminum silicate, a major amount ofgasoline and only very little middle distillate is obtained, but a verylarge amount of unchanged residue boiling in the range of the feedremains.

When a feedstock containing asphalt is processed over a zeolite aluminasupported catalyst, cracking to gasoline is considerably lessened,although more middle distillate is obtained. In this case also a largeresidue boiling in the range of the feedstock remains.

it is the object of this invention to prepare still further im' provedcatalyst carriers or compositions containing crystalline zeolites whichin particular have increased cracking activity.

Another object of the invention is to provide a hydrocracking processusing the said catalysts.

These objects are achieved with the hydrocarbon conversion catalystsaccording to the invention which contain from 0.2 to 35 percent byweight of at least one of nickel and molybdenum on a solid acid carrierwhich contains in intimate mixture from 10 to 90 percent by weight of acrystalline zeolite having a silica:alumina ratio in the range of l to 6and whose alkali metal cation has been removed to the extent of at least30 percent, and from 90 to 10 percent by weight of aluminum oxide andmagnesium oxide in the ratio of the oxides offrom l:lto :1.

The term "crystalline zeolite is used in the present specification todenote a natural or synthetic crystalline alkali metal aluminum silicatein which the molar ratio of SiO to Algoa may be from 1 to 6 or more (of.for example "Proceedings of the Sixth World Petroleum Congress, SectionIII, pages 1 ct seq.

The pore opening in the zeolite generally increases as the molar ratioof SiO to Al,0 increases. Zeolites having low Si0,:Al,b83 ratios, forexample from I to 2.5 may be used for conversion reactions with lowmolecular weight hydrocarbons. When hydrocarbons having higher molecularweight are used in the conversion reaction, it is advantageous to usezeolites having a higher SiO,,:Al,O ratio, for example of from 2.4 to 5.

The catalyst composed of crystalline zeolite and a mixture or compoundof oxides-of magnesium and aluminum may contain from 10 to 90 percent byweight, advantageously from to percent by weight, particularly from 50to 70 percent by weight, of the crystalline zeolite.

The ratio by weight of magnesia to alumina may be from 1:10 to 10:1,particularly from 1:4 to 4:1. A preferred ratio is about 1 mole ofmagnesium oxide to about 1 mole of aluminum oxide, i.e. about in theratio of the components in a spine].

The oxides may be mixed mechanically, for example by grinding. Themixture of oxides may however be prepared by precipitation from aqueoussolutions of salts of magnesium and aluminum. it is also possible toprecipitate only one component (for example magnesium oxide) onto theother component (aluminum oxide).

Chlorides nitrates, acetates or sulfates may be used for example as thesalts of aluminum and magnesium from which the mixed oxides areprecipitated. Ammonia is particularly suitable as precipitant. it isadvantageous to precipitate the oxides from a solution of the salts atelevated temperature, for example at from 40 to C.

According to one embodiment of the invention, the mixture of magnesiumoxide and aluminum oxide or the mixed oxides of aluminum and magnesium(which may if desired contain further magnesium oxide and/or aluminumoxide) are mixed intimately with the crystalline zeolite. Mixing may becarried out in the usual way, for example by grinding the substances ina ball mill.

in another method of making the catalyst carrier, the crystallinezeolite may be mixed with the still moist paste of the oxides ofmagnesium and aluminum or the still moist paste of the mixed oxides ofaluminum and magnesium (which may contain further magnesium oxide and/oraluminum oxide). The mixture is then dried, shaped and calcined.

Since the catalyst carrier according to the invention should contain aslittle alkali as possible, the alkali content of the crystalline zeolite(originally present as alkali metal aluminum silicate) is decreased bycation exchange. This may be done prior to the mixing of the zeolitewith the oxide mixture or after such mixing.

Inorganic salts, for example soluble compounds of silver, copper,calcium, magnesium, cadmium, ammonium, chromium, vanadium, iron, nickel,cobalt, manganese or zinc and also compounds of precious metals or rareearths are generally used for exchange of the alkali metal ions of thezeolite for other cations. Mixtures of solutions of different salts mayalso be used.

As a rule the alkali metal of the crystalline zeolite is exchanged tothe extent of up to percent, preferably up to 90 percent. It has provedto be advantageous for at least 30 percent, advantageously 45 percent,of the alkali metal content to be replaced by the said cations.

Depending on the intended use, catalytically active metals and/or metalcompounds may be applied to the catalyst carriers thus prepared.

Application of the catalytically active metal and/or compound may becarried out during the production of the mixture of zeolite with theoxides of aluminum and magnesium. Thus the cataiytically active metal ormetal compound may be mixed with the still moist composition of themixture of zeolite with the oxides of aluminum and magnesium.

Soluble saits of catalytically active metals may also be used forexchanging the alkali metal ions of the zeolite. The salts of iron,cobalt, nickel, chromium, manganese, copper, silver and the preciousmetals are particularly suitable for this purpose.

Application of the catalyticaliy active metals and/or metal compoundsmay also be carried out by preparing a paste of the oxides and/or mixedoxides of aluminum and magnesium with the whole of the catalyticailyactive metals and/or metal compounds, adding the cation-exchangedzeolite, drying, shaping and calcining.

The catalytically active metals and/or metal compounds should as a ruleamount to from 0.2 to 35 percent by weight of the finished cataiyst inthe catalysts according to this invention, which are particularlysuitable for hydrocracking.

The catalysts according to the invention are particularly suitable forhydrocracking, i.e. hydrogenating cracking of hydrocarbons within knownlimits of temperature, pressure, amount of hydrogen and space velocity.This usually involves the treatment of crude oils, shale oils, crude oilresidues and their distillation products and conversion products withhydrogen or gas containing hydrogen at temperatures of from 250 to 480C. and at a pressure of from about 50 to 300 atmospheres. The feedstockis used in amounts of from 0.2 to 5 kg. perliter of catalyst perhour.The amount of hydrogen supplied to the reactor is between 150 and 5000liters per kilogram of hydrocarbon to be converted per hour.

Catalysts which are suitable for hydrocracking may have a molar ratio ofSi :Al,O in the crystalline zeolites of from 1:1 to 1. Since the poreopening in the zeolites increases with increasing SiO,:Al O molar ratio,zeolites having a molar ratio of SiO AI O of more than 2:1, especiallymore than 2.421, particularly 2.7:1 to 6:1, are preferred forhydrocracking highboiling hydrocarbons. 1f low-boiling hydrocarbons suchas light naphtha and naphtha are to be hydrocracked, crystallinezeolites having a molar ratio of SiO :1\l of down to 1:1 may also beused.

Metals and/or metal compounds having catalytic activity are added inknown manner by mixing or impregnation to the carrier consisting ofcrystalline zeolite and magnesium oxide and aluminum oxide forpreparation of the catalysts suitable for hydrocracking. Metals andmetal compounds of subgroups 5 and 6 and of group 8 of the PeriodicSystem are suitable. Examples of suitable metals are nickel and/ormolybdenum. The finished catalyst may contain one or more than one ofthese catalytically active metals or metal compounds.

EXAMPLE I 24.66 A is treated twice, each time with a 10 percent solutionof cerium chloride which contains 2 percent of ammonium chloride at 80C. for 12 hours. The sodium content of the zeolite is then 1.6 percent.

Ammonium molybdate solution is added to some of the moist paste so thatafter drying, shaping and calcination, the finished catalyst contains 7percent of molybdenum oxide. Other portions of the moist zeolite pasteare mixed with amorphous aluminum silicate (75 percent of SiO;),gammaaluminum oxide, magnesium oxide/aluminum oxide spinel or magnesiumoxide/aluminum oxide percent magnesium oxide).

The amounts are chosen so that in the finished dried carrier in eachcase 70 percent of zeolite and 30 percent of amorphous carrier materialare present. The carrier is also treated with such an amount of ammoniummolybdate solution that after the catalyst has been dried, shaped andcalcined it contains 7 percent. of molybdenum oxide.

A residue, boiling above 360' C., from a Near Eastern crude oil having aspecific gravity at 70 C. of 0.954, 4.3 percent of sulfur, 10.8 percentof hydrogen, 3.6 percent of asphalt, 12.2 percent of Conradson carbon(all by weight), 62 ppm. of vanadium and 20 p.p.m. of nickel is passedunder the conditions specified in the follbwing table l00 c.c.m. ofoneof invention may be clearly seen from these comparative ex eriments;as may be seen from the final column in the table, t ese catalysts havea very high cracking activity. The product consists to the extent ofmore than 45 percent by weight of gasoline boiling at up to 185 C.; alarge amount of middle distillate is also obtained. The residue boilingabove 350 C. and in the boiling rangeof the feedstock is only 36.5percent or 38.6 percent by weight, i.e. considerably less than in thecomparative tests, with an adequate degradation of asphalt. When acatalyst having a pure zeolitic carrier is used according to the firstcolumn in the table, even an increase in the content of asphalt in theresidue is observed.

% of asphalt therein We claim:

1. in a process for hydrocracking an asphaltic heavy hydrocarbon crudeoil residue at temperatures ranging from 250 and 480 C., pressuresranging from 50 to 300 at mospheres, hourly space velocities rangingfrom 0.2 to 5 kg. per liter of catalyst and a hydrogen throughput of 150to 5000 liters per kilogram of oil in the presence of a catalystcontaining at least one metal selected from the group consisting of themetals of Groups VIB and VIII of the Periodic Table applied to a solidacidic support, said support comprising an alkali ion-exchanged zeolitedistributed in a matrix of inorganic oxides, the improvement whichcomprises contacting an asphaltic heavy hydrocarbon residue, boilingabove 360 C., in the presence of hydrogen with a catalyst comprising ametal component selected from the group consisting of nickel andmolybdenum, and both nickel and molybdenum and deposited in an amount offrom 5 to 25 percent by weight on a solid acidic support which is anintimate mixture 10 to percent by weight of a crystalline zeolite whichhas a silica/alumina molar ratio of from 2.7:1 to 6:1 and whose alkalications have been removed to the extent of at least 30 percent, and from90 to 10 percent of alumina and magnesia, the ratio ofsaid oxides beingfrom 1:10 to 10:1.

2. A process according to claim 1 wherein the alumina and magnesia arepresent as a physical mixture thereof.

3. A process according to claim 1 wherein the alumina and magnesia arederived by coprecipitation of salts thereof and calcination.

4. A process according to claim 1 wherein the alumina and magnesia ratiois in the range of from 1:4 to 4: 1.

5. A process according to claim 1, wherein the alumina and magnesiaconstitute a spinel.

2. A process according to claim 1 wherein the alumina and magnesia arepresent as a physical mixture thereof.
 3. A process according to claim 1wherein the alumina and magnesia are derived by coprecipitation of saltsthereof and calcination.
 4. A process according to claim 1 wherein thealumina and magnesia ratio is in the range of from 1:4 to 4:1.
 5. Aprocess according to claim 1, wherein the alumina and magnesiaconstitute a spinel.